Across the world, J. K. Rowling's new book has been rocketing to the top of the bestsellers lists within a few days of its release. It's no surprise that reviews have been luke-warm so far - Potter-madness was always going to be a tough act to follow, but I look forward to trying Rowling out as an adult author sometime soon. Equally unsurprising is the presence of assorted versions of the 50 Shades trilogy, and Mark Owen's account of the mission to capture Osama Bin Laden. Jeff Kinney and Rick Riordan the early favourites in this season's childrens reads too.

The top ten bestselling books in September, according to Amazon US:

The Casual Vacancy by J.K. Rowling book cover

J. K. Rowling 
$20.90 from Amazon
The Mark of Athena by Rick Riordan book cover

Rick Riordan
$11.04 from Amazon
No Easy Day by Mark Owen book cover

Mark Owen 
$15.65 from Amazon
Fifty Shades of Grey by E L James book cover

E L James
$9.57 from Amazon
Fifty Shades Trilogy by E L James book cover

E L James
$27.74 from Amazon
The Third Wheel by Jeff Kinney book cover

Jeff Kinney 
$7.75 from Amazon
Killing Kennedy by Bill O'Reilly book cover

Bill O'Reilly
$16.28 from Amazon
Eat to Liver by Joel Fuhrman book cover

Joel Fuhrman
$5.99 from Amazon
Fifty Shades Darker by E L James book cover

E L James 
$9.57 from Amazon
Gone Girl by Gillian Flynn book cover

Gillian Flynn
$13.94 from Amazon
Prices correct on 30/09/2012